IPCC-seminaari ilmastonmuutoksen vaikutuksista, sopeutumisesta ja haavoittuvuudesta, Helsingin yliopisto, Introduction to the Working Group II Fourth Assessment Report (AR4) Timothy Carter Co-ordinating Lead Author, Chapter 2 Finnish Environment Institute (SYKE) Intergovernmental Panel on Climate Change Working Group II Climate Change 2007: Impacts, adaptation and vulnerability

IPCC-seminaari ilmastonmuutoksen vaikutuksista, sopeutumisesta ja haavoittuvuudesta, Helsingin yliopisto, The process Five year process 2003 – Authors –49 Co-ordinating Lead Authors (CLAs) and 125 Lead Authors (LAs) from 65 countries –220 Contributing Authors (CAs) 45 Review Editors (REs) 4 Review Cycles 1183 Expert Reviewers 49,610 Review Comments Approved in Brussels, 6 April 2007

IPCC-seminaari ilmastonmuutoksen vaikutuksista, sopeutumisesta ja haavoittuvuudesta, Helsingin yliopisto, OUTLINE FOR WORKING GROUP II : IPCC FOURTH ASSESSMENT REPORT CLIMATE CHANGE: IMPACTS, ADAPTATION AND VULNERABILITY Summary for Policymakers Technical Summary Introduction I. ASSESSMENT OF OBSERVED CHANGES 1. Assessment of observed changes and responses in natural and managed systems II. ASSESSMENT OF FUTURE IMPACTS AND ADAPTATION: SECTORS AND SYSTEMS 2. New assessment methods and the characterisation of future conditions 3. Fresh water resources and their management 4. Ecosystems, their properties, goods and services 5. Food, fibre and forest products 6. Coastal systems and low-lying areas 7. Industry, settlement, and society 8. Human health III. ASSESSMENT OF FUTURE IMPACTS AND ADAPTATION: REGIONS 9. Africa 10. Asia 11. Australia and New Zealand 12. Europe 13. Latin America 14. North America 15. Polar Regions (Arctic and Antarctic) 16. Small Islands IV. ASSESSMENT OF RESPONSES TO IMPACTS 17. Assessment of adaptation practices, options, constraints and capacity 18. Inter-relationships between adaptation and mitigation 19. Assessing key vulnerabilities and the risk from climate change 20. Perspectives on climate change and sustainability Timothy Carter, CLA Kimmo Ruosteenoja, CA Seppo Kellomäki, RE Approved, line by line, in Brussels, 6 April 2007

IPCC-seminaari ilmastonmuutoksen vaikutuksista, sopeutumisesta ja haavoittuvuudesta, Helsingin yliopisto, Observed impacts (Links to WG I)

IPCC-seminaari ilmastonmuutoksen vaikutuksista, sopeutumisesta ja haavoittuvuudesta, Helsingin yliopisto, Working Group I Figure SPM-3 Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level. [WG I, SPM, p5] Most of the observed increase in globally averaged temperatures since the mid- 20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations [WG I SPM, p. 10]

IPCC-seminaari ilmastonmuutoksen vaikutuksista, sopeutumisesta ja haavoittuvuudesta, Helsingin yliopisto, Future impacts (Links to WG I)

IPCC-seminaari ilmastonmuutoksen vaikutuksista, sopeutumisesta ja haavoittuvuudesta, Helsingin yliopisto, Working Group I Figure SPM-4 Continued greenhouse gas emissions at or above current rates would cause further warming and induce many changes in the global climate system during the 21st century that would very likely be larger than those observed during the 20th century. [WG I, SPM, p. 13]

IPCC-seminaari ilmastonmuutoksen vaikutuksista, sopeutumisesta ja haavoittuvuudesta, Helsingin yliopisto, Responding to climate change: adaptation and mitigation

Global temperature increase (°C) Risk management through mitigation limits warming Risk management through adaptation reduces damages Current climate risks are also reduced by adaptation Year WG II, Ch 2, Fig. 2.1 (simplified) Synthesis of risk assessment approach to global warming Probability Low probability Least likely Moderately likely Highly likely Almost certain Happening now Consequence Extreme outcomes Considerable damage to most systems Increased damage to most systems, fewer positives Damage to the most sensitive, many positives Vulnerable to current climate Risk = Probability x Consequence